User's Manual

350-Watt Digital VHF LB Transmitter Chapter 3, Installation and Setup Procedure
DT325B, Rev. 0 3-5
do not rub against each other and have
no restrictions to free movement.
Adjustments to the position of the trays
may be necessary. To accomplish this,
loosen the cabinet slide mounting bolts
that hold the front of the slide to the
mounting frame of the cabinet and move
the tray up or down as needed to correct
for the rubbing.
The air intake to the transmitter is
intended for room air only. The cabinet
should be positioned with consideration
given to adequate air intake and exhaust,
the opening of the rear door, access to
the trays (including sliding them out for
testing), the main AC hookup, and the
installation of the output transmission
line. The cabinet should be grounded
using copper strapping material and
should also be permanently mounted to
the floor of the site using the holes in the
bottom of the cabinet.
3.3 Input and Output Connections to
the Transmitter
3.3.1 Main AC Connection to the
Transmitter System
Once the cabinet is in place, the
connection of the Main AC to the cabinet
is ready to be made.
Caution: Before connecting the
transmitter to the AC voltage, make
certain that all of the circuit breakers
associated with the transmitter are
switched off.
The main AC input circuit to the DT325B
is a 30-amp, 220-VAC line, using AWG 6
wire, inside of 1-1/4-inch conduits to
each cabinet assembly. The 220 VAC
input connections are made to the
terminal block TB1, which is part of the
AC junction box, mounted near the upper
right-hand, rear portion of the cabinet:
terminals 1 and 2 (220 VAC) and
terminal 3 (chassis ground). See Figure
3-3.
Figure 3-3: AC Input Box Assembly
Check that the AC power cords from the
Driver/Amplifier Chassis Assembly and
the Axciter Modulator Tray connect
directly to the UPS or to the AC outlet
assembly connected to the UPS in the
Cabinet. Check that the AC power cord
from the VHF Amplifier Tray connects to
the AC outlet assembly not connected to
the UPS in the Cabinet.
3.3.2 Input Connections to the
Transmitter System
Connect the SMPTE 310 input to J27
located on the rear panel of the (A24)
Axciter Modulator Tray. If an external 10
MHz reference is used, connect it to J9
located on the rear panel of the (A24)
Axciter Modulator Tray. If the external
10MHz is not used an internally
generated 10MHz is produced by the
Axciter Modulator for use in the
transmitter. Check that the DTV output
of the Axciter at J40 connects to J68, the
IF Input jack, on the rear panel of the
Driver/Amplifier Chassis Assembly. Check
that the 1GHz output of the Axciter at
J15 connects to J40 on the rear panel of
the Driver/Amplifier Chassis Assembly.
Check that the forward power sample,
pre-filtering, of the VHF amplifier tray,
from the (A16) pre-filter coupler
connects to J1, on the K2 relay. Check
that the forward power sample, post-
filtering, of the output of the transmitter
from the (A11) post-filter coupler
connects to J2, on the K2 relay. Check
that the selected output of the K2 relay
at J3 connects to the rear of the
driver/amplifier chassis assembly at the
SMA Jack J41. This sample is used by
the Axciter system in the adaptive
equalization process.